Monday, April 05, 2010
Ewww, growing bacteria for science
Bacteria are microorganisms that grow everywhere. We can collect and grow them in specially prepared petri dishes. We bought petri dishes at Classroom Corner they didn't have the agar for the dishes so I just made my own.
Agar recipe that I used
1 pack Knox gelatin
3/4 cup of boiling water
1 bouillon cube
then pour into the sterile petri dishes and let set in the fridge for a little while.
After the petri dishes were ready we just used a cotton swab to go around the house and rub it on something and then gently rubbed it on the agar. After 2 days nothing was growing but on day 3 we started seeing bacteria begin to grow and at day 6 it was disgusting and day 9 the whole dish was full. Very gross but educational and the kids think more about germs and what could possible be growing on all surfaces around our house and out in public.